Monoazo-dyestuffs



Patented Apr. 5, 1938 UNITED STATES PATENT OFFICE ,MONOAZO-DYESTUFFS Richard Fleischhauer, Frankfort-on-the-Main- Fechenheim, Germany, assignor to General Aniline Works, Inc. New York, N. Y., a corporation of Delaware No Drawing. Application December- 1, 1936, Se-

rial No. 113,611. In Germany'December 2,

4 Claims.

My present invention relates to monoazo dyestuffs, more particularly to those of the general formula 0H NHOOCHa wherein R stands for a member of the group consisting of hydrogen and an alkyl group containing at the most 3 carbon atoms and one X means hydrogen and the other a sulfonicacid group.

The new dyestuffs are obtained by combining diazo compounds of aromatic amines of the formula ' N NE: C

CHsCO 17.8 parts of l-(acetyl-ethyl-amino) -4-aminobenzene are diazotized in the usual manner in an aqueous medium. The diazo solution thus obtained is added while cooling to a solution containing an excess of sodium carbonate and 37 parts of 1 -acetylamino- 8 -naphthol-3,6-disulionic acid. When the formation of the dyestuff has been finished 'it is isolated and dried. The new dyestufi of the formula l l OH 'r niooonl is a dark red water soluble powder and dyes wool bright bluish red shades and exhibits an excellent levelling power.

Example 2 When using as a diazo component the diazo compound of 20.6 parts of 1%acety1-isobutylamino) -4-aminobenzene and carrying out the reaction otherwise as described in Example 1 the formed dyestuff of the formula (l)H NHCO CH:

HOaS SOaH is when dry a bluish red water soluble powder and dyes wool bright bluish red shades and exhibits an excellent levelling power.

Similar dyestuffs are obtained when starting from the diazo compound of l-[acetyl-n-propyl- (and n-butyl) -amino] -4=-amino-benzene.

' Example 3 16.4 parts of 1-(acetyl-methyl-amino) -4-amino-benzene are diazotized in the usual manner in an aqueous medium. The diazo solution thus obtained is added while cooling to a solution containing an excess of sodium carbonate and 37 parts of 1-acety1-amino-8-naphthol-4,6-disulfonic acid. When the formation of the dyestufi has been finished it is isolated and dried. The new dyestuflz' of the formula 0H NHCOCH:

is a red water soluble powder and dyes wool bright red shades and exhibits an excellent levelling power.

Similar dyestuffs are obtained when starting from the other diazo compounds, aslmentioned in the foregoing examples.

I claim:

1. Monoazo dyestuffs of the general formula OH NHCOCH:

2. The monoazo dyestuff of the formula OH ITIHOOCH:

which dyestuif is a dark red water soluble powder and dyes wool bright bluish red shades and exhibits an excellent levelling power.

3. The monoazo dyestufi of the formula OH NHOOCHa CH3 CH3 which dyestuff is when dry 1-). bluish red water soluble powder and dyes wool bright bluish red shades and exhibits an excellent levelling power.

4. The monoazo dyestuff of the formula OH NHCOOH:

which dyestufi is when dry a red water soluble powder and dyes wool bright red shades and exhibits an excellent levelling power.

RICHARD FLEISCHHAUER. 

